COPENDING U.S. APPLICATION
The Parvulescu and Zidel U.S. patent application entitled "Two-Way Voice Messaging Terminal Having A Speech To Text Converter" bearing Ser. No. 08/573,624, filed Dec. 18, 1995, and assigned to the same assignee as the instant application, is referenced herein as a source, when issued, for providing details of a pager transceiver having two-way voice messaging capabilities suitable for use with embodiments of the present invention.
Several varieties of wireless personal communication devices (PCD) are currently available for business and personal use. Portable telephones provide the user with freedom from being tethered to a wall mounted conventional telephone jack. Both digital and analog cellular telephone systems provide greater freedom to roam within a service area and provide connectivity with the public switched telephone network (PSTN) from isolated locations, as well as from transportation systems such as planes, trains and automobiles. Cellular devices which handle data as well as voice information are also known. Although frequently very convenient, cellular telephone systems are both relatively complex and relatively expensive for many users. A cellular telephone infrastructure is also relatively expensive to install and maintain. Perhaps as a result, market penetration for cellular services in the United States is currently on the order of about 10% and is even lower in overseas locations.
Another type of currently available communication system, which those of skill in the art would distinguish from a cellular system, is known as a specialized mobile radio (SMR) system. Specialized mobile radio systems using packet data schemes are currently in use, for example, in directing fleets of delivery trucks and to expedite check-in/check-out procedures at rent-a-car vendors. Such systems are frequently text only systems, operated in a broadcast mode to a fleet of subscribers. Specialized mobile radio systems incorporating digital voice messaging capability are disclosed in, for example, Burke U.S. Pat. No. 4,495,647 (issued Jan. 22, 1985) and Burke U.S. Pat. No. 4,468,813 (issued Aug. 28, 1984). Although apparently acceptable for some business and military applications, specialized mobile radio systems (including mobile data systems) are typically too complex and expensive for consumer use and cannot be characterized as having met the needs of the consumer successfully.
A third type of PCD which has become quite popular with the public is a pager. Conventional pagers are small, easy to operate, and provide limited but useful communication capabilities, such as the fact that the user has been telephoned and a telephone number to return a call to, or other brief messages. The information which may be communicated from a message handling center to a remote portable pager is limited both by the memory and display limitations of the pager/receiver device and by communication protocol formats used in the paging industry, discussed, for example in Mori U.S. Pat. No. 4,353,065 (issued Oct. 5, 1982) and U.S. Pat. No. 4,618,860 (issued Oct. 21, 1986).
As discussed above, conventional pagers are typically capable of handling only brief text messages in a receive-only mode. A few known pagers are capable of limited two-way communications, as, for example, through user selection of a short response from among a menu of possible responses, as disclosed in Davis U.S. Pat. No. 5,153,582 (issued Oct. 6, 1992). However, available two-way pagers are limited in several respects. The hardware constraints of the pagers, the communication protocol message link limitations, and the ease of operation both for the person being paged and the person calling the paging service leave much to be desired.
For example, a need exists for a pager which is relatively simple to manufacture and operate, which provides two-way communication and is also relatively inexpensive. An exemplary use of such a device would be for children to communicate with their parents such information as when the children's after school activities are completed or when they have arrived at a location to which they were traveling alone. Moreover, children who cannot read would understandably have difficulty in using conventional pagers. Adults who are not comfortable with modern communication technology and need only to exchange brief messages inexpensively would also be well served by such a device. Finally, visually impaired individuals, and those with limited manual dexterity, such as arthritis patients, are essentially excluded from the benefits provided to the larger population by current paging devices. These individuals may either have difficulty reading current pager displays or in operating the small buttons necessary to compose even a short text message on a conventional pager.
One available improvement on conventional pagers is the provision of a one-way receive-only voice messaging capability. In such a system, analogously to a telephone answering machine or voice mail system, a voice message is received at the message handling center from the PSTN. Next, the analog voice signal is digitized and coded by a device known as a coder/decoder (CODEC) using one of a number of known coding systems. Known voice coding systems include MBE (Multi-Band Excitation), SBE (Single-Band Excitation), SBC (Sub-Band Coding), Harmonic Coding, LPC (Linear Predictive Coding), DCT (Discreet Cosigne Transport), MDCT (Modified DCT), FFT (Fast Fourier Transform), CELP (Code Excited Linear Prediction), VSELP (Vector Sum Excited Linear Prediction) and RPE-LTP (Regular Pulse Excitation--Long Term Prediction), among others. After coding, a message is transmitted by a message handling center, then received, decoded and played by the pager unit. Examples of pagers providing such improvements over conventional paging technology are found in Davis U.S. Pat. No. 4,701,943 (issued Oct. 20, 1987) and Fisch U.S. Pat. No. 4,949,085 (issued Aug. 14, 1990). Such devices, although they represent apparent improvements over the conventional limited message length text pager, still posses ease of use, complexity and cost disadvantages. Most significantly, such devices, because they are one-way receive only pagers, do not meet the special needs of children and the visually impaired for two-way short message communication.
Other unmet needs are evident. For example, the preferred portable voice message transceiver terminal disclosed in the co-pending application uses a solid state memory device to record voice messages to be transmitted by the user. It will be apparent that in such a device, the length of the message to be recorded and sent is by necessity rather short since cost (and to some extent device size) is dependent upon the amount of memory provided, which directly controls maximum message length. Moreover, cost of use is related to length of the transmission. Transmissions may also be limited by communication protocol formats which limit, for example, maximum word length.
Thus, a user of the above discussed devices must necessarily keep his or her message brief However, conventional pagers and similar telecommunication devices have not been faced with the problem of stimulating the user to message brevity. In fact, for cellular telephone devices where fees to the service provider are based upon length of the communication, the economic impetus has been just the reverse.
Thus, a need exists for a duration remaining indicator in voice messaging. It would be advantageous if such an indicator made minimal demands on a user's conscious attention. More specifically, certain categories of two-way voice pager users have special needs for indicators suited to their capabilities, and would benefit from having communication opportunities made move fully available to them through provision of two-way voice pagers incorporating the invention disclosed below.